Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed documents

Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed documents

Some documents that listed on subsystem-apis have 'Linux' or 'The Linux'
title prefixes.  It's duplicated information, and makes finding the
document of interest with human eyes not easy.  Remove the prefixes from
the titles.

Signed-off-by: SeongJae Park <sj@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20230122184834.181977-1-sj@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>